Digital cameras usually comprise an automatic aperture switching device for automatically switching the camera aperture. The aperture switching device usually comprises driver means which is automatically controlled to drive a transmission mechanism for moving an aperture plate so as to change the camera aperture. The driver is usually operated magnetically by means of wire winding constituted by a plurality of turns. The more the turns are, the great the power it outputs, but the greater space it takes. Thus it is desired to provide an aperture switching device which may effectively change the aperture, but takes a smaller space.